The present invention refers to an apparatus for continuously making a multilayered, flat workpiece, and in particular to an apparatus in which the layer materials for the workpiece are conducted through a reaction zone formed between two press belts, heated there, with pressure being exerted on the layer materials by at least one press belt, and with at least one pressure compartment, which cooperates with a pressure plate situated on the press belt distant side, being associated to this press belt in the reaction zone at the layer-distant side thereof and filled with a gaseous or liquid pressure fluid.
German Pat. No. 33 13 406 describes continuously operating presses with at least one continuous belt which is pressed by a pressure fluid against the workpiece. A pressure fluid is introduced into a rectangular pressure compartment which is situated adjacent the press belt on the side of a pressure plate facing the press belt and is sealed by a circulating sealing strip. The sealing strip is connected with a correspondingly rectangular mounting frame which is guided in a groove of the pressure plate for movement therein and pressurized in direction towards the press belt which slides along this sealing strip.
A drawback of this conventional press is the resulting loss of pressure fluid through the gap between the sealing strip and the circulating press belt in cases of trouble such as uneven wear of the sealing strip, jamming of the mounting frame in the groove of the pressure plate, change of width of the workpiece, or the like, and thus surface defects of the finished product are experienced.
German Pat. No. 29 379 72 discloses an apparatus for applying a surface pressure on advancing workpieces by at least one circulating press belt which is forced onto the workpiece by a pressure fluid contained in pressure compartments arranged successively on the inside of the press belt along the effective pressure surface of the press belt and sealed by respective sealing strips.
This apparatus, too, results in case of trouble during operation in a loss of pressure fluid which escapes through the gap between the sealing strip and the press belt.